/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans.factory.support;

import org.springframework.beans.BeanMetadataAttributeAccessor;
import org.springframework.util.Assert;

/**
 * Qualifier for resolving autowire candidates. A bean definition that
 * includes one or more such qualifiers enables fine-grained matching
 * against annotations on a field or parameter to be autowired.
 *
 * @author Mark Fisher
 * @author Juergen Hoeller
 * @see org.springframework.beans.factory.annotation.Qualifier
 * @since 2.5
 */
@SuppressWarnings("serial")
public class AutowireCandidateQualifier extends BeanMetadataAttributeAccessor {

    public static final String VALUE_KEY = "value";

    private final String typeName;


    /**
     * Construct a qualifier to match against an annotation of the
     * given type.
     *
     * @param type the annotation type
     */
    public AutowireCandidateQualifier(Class<?> type) {
        this(type.getName());
    }

    /**
     * Construct a qualifier to match against an annotation of the
     * given type name.
     * <p>The type name may match the fully-qualified class name of
     * the annotation or the short class name (without the package).
     *
     * @param typeName the name of the annotation type
     */
    public AutowireCandidateQualifier(String typeName) {
        Assert.notNull(typeName, "Type name must not be null");
        this.typeName = typeName;
    }

    /**
     * Construct a qualifier to match against an annotation of the
     * given type whose {@code value} attribute also matches
     * the specified value.
     *
     * @param type  the annotation type
     * @param value the annotation value to match
     */
    public AutowireCandidateQualifier(Class<?> type, Object value) {
        this(type.getName(), value);
    }

    /**
     * Construct a qualifier to match against an annotation of the
     * given type name whose {@code value} attribute also matches
     * the specified value.
     * <p>The type name may match the fully-qualified class name of
     * the annotation or the short class name (without the package).
     *
     * @param typeName the name of the annotation type
     * @param value    the annotation value to match
     */
    public AutowireCandidateQualifier(String typeName, Object value) {
        Assert.notNull(typeName, "Type name must not be null");
        this.typeName = typeName;
        setAttribute(VALUE_KEY, value);
    }


    /**
     * Retrieve the type name. This value will be the same as the
     * type name provided to the constructor or the fully-qualified
     * class name if a Class instance was provided to the constructor.
     */
    public String getTypeName() {
        return this.typeName;
    }

}
